High quality conveyors, stackers and stockpilers can be found in all successful quarry operations. Guy Woodford looks at the latest products of some leading sector names, along with the production ethos of one prominent European conveyor and stacker solution firm.
In many industrial processes, such as the cement industry, the regularity of the raw materials used plays an important role in the manufacture of products. This uniform consistency is ensured through blending beds located within the storage facility. As a system supplier, the Germany-headquartered
Be it houses, bridges or tunnels, cement is the material that holds everything together. However, a bag of this material has already come a long way before it arrives at the building site. When the component raw materials are mined and transformed into cement at the cement plant, they pass through many different stages. The most important raw materials for cement production are limestone, clay and marl. Workers break them out of quarries or extract them with heavy tools. Wheeled loaders and dump trucks transport the raw materials to the crushing facilities. There, the rocks are crushed to the approximate size of road gravel. These rocks then arrive at the cement works via kilometres-long belt conveyors.
A consistent quality must be ensured so that the producers can further process the material to high-quality cement – fluctuations in the material characteristics must not occur. Therefore, a belt conveyor transports the individual raw materials to the blending beds. These storage location systems mix and homogenise the raw materials.
For almost 80 years, Beumer has been developing tailor-made system solutions in conveying technology for the stone and quarry industry, power plant industry, mining (ores and coal) as well as the logistics industry (harbours and trans-shipment terminals). Furthermore, the specialists have comprehensive expertise in engineering of blending beds and stockpiles. Through what the firm says is structural analysis of the associated storage depots and calculation of dimensions, Beumer is able to provide a design. The blending beds are customised according to their requirements. Beumer proposes either longitudinal or circular stockpile designs. The recommended design shape results from the spatial conditions and the amount of the material to be stored. Depending on the field of application, Beumer designed blending beds can be used at extreme ambient temperatures, for very high entry conveying capacities, as well as for the highest degree of homogenisation required. Beumer also provides material-specific detailed solutions with robust and low-wear equipment. The environmental impacts are also said by the company to be very low as minimal noise and dust occurs during operation. Blending beds can be set up both outdoors and indoors.
The stacker and the bridge scraper are the basis for a blending bed. If they are perfectly designed, the user will obtain an optimum blending effect. Beumer offers stackers that stack the bulk material efficiently and effectively. In the end, the stockpile has been raised so reliably that its cross-section shows as many layers of equal material as possible. The stackers can be of fixed or mobile types, depending on the requirement. In case of circular stockpiles the stackers are mounted onto a column and with a longitudinal blending bed, they are mounted on rails. The stackers are designed as fixed, raisable and pivotable booms with conveying capacities of up to 4,000tonnes/hour. The choice of the right system depends on different factors, as for example, the shape and size of the stockpile, the material, the throughput and the desired mobility.
Lastly, the bridge scraper homogenises the material. It has a mobile rake on each side. The material is removed in layers by stroking the face of the stockpile with the rake. The scraper blades move the bulk material towards the belt conveyor which runs parallel to the stockpile. BEUMER bridge scrapers are not only robust, but they also transport the bulk material so that the product is handled gently. This makes them suitable for a variety of bulk materials. Their continuous and comparably simple working motions allow for a fully automated operation and ensure a constant and steady flow of the bulk material.
In the past, Beumer teams have completed eye-catching projects in this field. One such example is an installation of a bridge scraper in Russia, which works at an ambient temperature as low as -40C. The rail width is 34 metres and this bridge scraper is designed for a conveying capacity of 500tonnes/hour. Furthermore, Beumer has developed a stacker for coal mining, which is operated at ambient temperatures of -20C. This boom has a length of 41 metres and the belt width measures 1.6 metres. It transports 2,250tonnes of bulk material/hour. Beumer also engineered a bridge scraper with a rail width of 55metres that conveys 1,100tonnes of coal/hour.
Martin Engineering, the innovative US-based conveyor solutions company, has redesigned an integral conveyor transfer point component to eliminate worker entry into the chute box for safer replacement, easier maintenance and reduced downtime.
Conventional wear liners have historically been installed inside the chute, but the EVO External Wear Liner from
“The wear liner is essentially considered a sacrificial layer,” explains Daniel Marshall, product engineer at Martin Engineering. “Removal and replacement used to be a gruelling job that could require multiple workers and days of scheduled downtime. Our goals with this design were to significantly cut the installation and service time, while reducing risk and improving safety.”
Previous designs securely welded the wear liner to the inside of the chute, with only the skirt seal located on the outside. The logic behind the conventional design is for the wear liner to protect the skirtboard, which is typically 0.63cm sheet metal and not strong enough to withstand the sustained force and abrasion from bulk material.
Instead, Martin Engineering designers came up with the idea of raising the chute work about 10cm above the belt, out of the way of the material, then putting the wear liner on the outside. Using this approach, the material still hits the liner and doesn’t damage the chute. “It was a real light bulb moment,” Marshall said. “We were surprised that no one had tried it before, as it has some obvious benefits.”
After elevating the chute box above the material flow, 0.95cm or 1.27cm thick abrasion-resistant liner plate (AR 400 or 500) is mounted on the outside of the chute, followed by the skirt seal. Mounting brackets with jackscrews provide a tight hold, with precision adjustment of the wear liner to reduce spillage. This system closes the gap between the liner and the sealer, thus eliminating abrasion from trapped material without interfering with existing supports. When accompanied by Martin Double Sided ApronSeal skirting and clamps, the system forms a tight belt seal, said to deliver outstanding fugitive material control.
Tracked and wheeled conveyors from
Wheeled units are road portable and can be hauled to different locations or relocated on site with the help of a truck. The tracked units make manoeuvring around a jobsite easy as they can move under their own power. They can be folded and loaded onto trailers for relocation from site to site.
IROCK builds the high-capacity conveyors with heavy-duty components and channel frames for durability and longevity. The units stockpile to heights over 10m and are used in sand and gravel, topsoil, coal, crushed stone and recycling applications.
The tracked T-8048 conveyor features a 1.21m-wide belt and stretches 24.38m long, and it can stockpile material up to 10.1m for more stacking before relocation. With the hydraulically adjustable tail section, operators can reduce the drop height of material onto the conveyor to lessen wear and minimise spillage. The T-8048 comes standard with a
IROCK’s wheeled M-5030, the M-6030 and M-8036 units feature a fifth wheel pin with a radial plate for 180° rotation. With its ability to stack in an arc, these units allow for optimal stockpiling capability and boost the efficiency of operations by reducing frequent material handling. A large receiving hopper reduces spillage and pairs well with larger screening and crushing plants.
The M-5030 features a 7.45kW electric motor and a 0.76m-wide, 15.24m-long conveyor that stockpiles to 6.7m. The M-6030 has a 7.45kW electric motor and a 0.76m-wide, 18.28m conveyor that can stockpile to 7.46m. Finally, the M-8036 features a CAT C2.2 engine rated at 37.28kW, and its 0.91m, 24.38m conveyor can stockpile to 9.14m.
Options for the wheeled conveyors include diesel hydraulic power pack, hydraulic raise and lower, brakes, light package, power travel and chevron belting.
Sidewall conveyor belt systems are among the most efficient means of transportation. Solutions that were unthinkable in years gone by are standard practice today thanks to new innovative research and development. Said to be at the forefront of current developments is PHOENIX S-Wall. Among corrugated sidewall belts, the solution from Phoenix has been one of the market leading products for many years. And while leading the way with a hot vulcanised bonding method, cold bonding is still very much a valid option for S-Wall. “This is a ‘best of both worlds’ approach for us. We offer a hot vulcanised product for specific applications, but we still achieve an extremely high bond strength with our cold bonded product. This allows us to offer a faster delivery time with a product that is easier to maintain at site,” explains Tom Webster, sales & application engineer at Thetford, county Norfolk, England-based Phoenix.
Phoenix is among the pioneers and industry leaders in the development and manufacture of conveyor belts. The company is recognised worldwide as a specialist in providing customised solutions for highly complex applications. PHOENIX S-Wall corrugated sidewall belts are suitable for vertical conveyance at angles of up to 90°, and are said to be ideal for applications within confined spaces. “Having been in the industry of manufacturing sidewall belting since 1984 we have the experience to offer a cold bonded product of the highest quality and standards“, emphasises Webster. There are many advantages to the cold bonding method: Aside from being a cost-efficient solution, Phoenix uses a specifically engineered cover grade to achieve a far superior bond strength to that of the competition. This results in a much reduced risk of profile separation. Maintenance at the installation site is also less complicated, as sidewalls and cleats can be interchanged far easier on a cold bonded belt.
At the expanded production facilities in Thetford, in addition to conventional production using the cold-bonding method, customers also have the option of having the corrugated sidewalls and cleats attached through hot vulcanisation. This is said to significantly increase the bond strength between the profiles and the base belt, resulting in a sidewall conveyor belt that can be used at high temperatures. “The main benefit for the hot vulcanised product is, among other things, the highest adhesion levels between the profiles and base belt. We use specially engineered vulcanising compounds which allow for a lifespan similar to that of the base belt, especially in applications where heat is involved,” says Webster. These vulcanised products are enabling us to handle materials at temperatures previously not possible with a sidewall conveyor belt.
In addition, a newly developed rubber compound for the corrugated sidewalls and cleats ensures that they cope with the high demands of steep angle conveying. These hard-wearing materials can significantly increase the service life of the belt and prevent time-intensive maintenance and repair work.
Superior Industries, Inc., a major American manufacturer and global supplier of bulk material processing and handling systems, has released version 12.0 of its telescoping radial stacker automation program. While the updated program does not affect the physical function of the machine, the appearance of the software received a major makeover.
The new, user-friendly screen design is equipped with bolder graphics and modern onscreen buttons to help users navigate the software more easily. In addition, says Superior’s in-house programmers, navigation was tweaked to help improve the user experience. Also new, the automation software is now equipped with onscreen access to the TeleStacker Conveyor owner’s manual and a running meter that reports the unit’s motor hours.
According to the company, TeleStacker Conveyors dating back to 1997 can be upgraded; however, existing owners should contact their Superior dealers for more information.
